Beginner's Guide

Do Killifish Need Aeration, Filter, and Heater?

Are you pondering adding Killifish to your fish tank? Are you wondering whether these small fish are high maintenance? Do you think they require a lot of aquarium equipment to keep healthy?  Do Killifish Need Aeration, Filter, and Heater?

The main thing to know about Killifish is that they are hardy fish that are easy to take care of. Hence, even though aeration and filter are recommended, it is not essential for Killifish but Killifish do require a heater as most Killifish require water temperatures of 72-75oF.

Nonetheless, before I move on to talking about how important aeration, filters, or heaters are for Killifish, let us look at what type of fish Killifish are, and what their ideal tank conditions consist of.

Background on Killifish

Killifish are hardy fish with long and slender bodies. However, there are altogether 1270 species of Killifish. Hence, there are some variations amongst these 1270 species of this fish.

Nonetheless, most Killifish are 1-2 inches long, whereas, some Killifish can grow up to 6 inches long. These fish are one of the most fascinating fish that exist due to their ability to survive and reproduce in unconditional environments. For instance, some species of Killifish can survive for months out of the water, whereas, others can reproduce in ponds and streams that dry up for a chunk of the year.

Killifish also display territorial behavior, especially amongst the male Killifish. However, they are easy to take care of due to their tendencies to occupy only the top portion of the tank. This in turn allows for the other fish species in the tank, who reside in the lower portions of the tank, to have their space.

Moreover, Killifish like to feed on aquatic arthropods. Hence, their diet consists mainly of worms, insect larvae, and aquatic crustaceans, which includes Shrimps.

You might like to read more about Fish Food 101: A Beginner’s Guide On How To Feed Aquarium Fish

Ideal Tank Conditions for Killifish

It is highly important to remember that your Killifish will prefer very little, or no water movement. Hence, it is best to place them in long and shallow tanks.

Your Killifish will also prefer to live in a tank with lots of live plants, especially floating plants. One of the most suitable plants for your Killifish is the Cryptocoryne. The reason your Killifish like to have plants around them is that they prefer low levels of lighting.

As mentioned earlier, they prefer the water temperature to be between 72-75oF. It is also best to maintain the pH level of the water between 6.0 and 7.0, and the total hardness between 7° and 10° (120 ppm to 160 ppm).

Water Changes

As with other fish species, doing a regular water change in a tank with Killifish is important. But how often should you perform this water change?

The answer is one one-third of water change per week is optimal. By doing this your Killifish will be happy and your fish tank will remain clean whilst maintaining the level of necessary bacteria.

You might like to read more about Is Too Much Water Change Harmful For Your Fish: How To Do It Safely

Do Killifish Need Aeration?

It is most important to understand what aeration does to a fish tank’s inhabitants, and why it is important.

Aeration can be increased most easily by inserting more plants into your fish tank. By doing this, it increases the oxygen level in the water, which the fish use to breathe and survive.

However, there are other ways of increasing aeration in the fish tank as well. This includes aerators such as airstones, bubble wands, LED bubblers, and more. What these aerators do is create water movement and increase the circulation of oxygen in the water.

Here is an article for you How To Maintain The Oxygen Level In Aquarium? Have a look!!

What type of Aerator should you get for your Killifish?

In the case of Killifish, as they do not prefer high water movement and prefer to live in low light tanks, it is best to add live plants to your fish tank. The live plants will not only increase the aeration in your fish tank but also give your Killifish the privacy they require.

It is key to note that if your fish tank is small (less than 20 gallons), then you should be mindful of not overcrowding your fish tank with plants. For instance, small volumes of water can easily become concentrated with waste products, which increases the level of ammonia and nitrites in the water. This increase in ammonia and nitrites can be very harmful to the fish.

Hence, it might be best to use an air-driven filter to nitrify the bacteria. This will break down the harmful ammonia and nitrites into nitrates, which will not harm your precious Killifish.

Here is an extra dose of knowledge for you Beneficial Bacteria In The Aquarium: What Are They And Is It Essential?

Do Killifish Need a Filter?

Before installing a filter in your fish tank, you need to decide how often you are willing to perform water changes. For instance, if you have a small fish tank (less than 20 gallons), then you will most likely need to use a filter. However, you can avoid investing a lot of money in a fancy filter if you are willing to perform 30% water changes once a week.

You might like to know more about Why Do Fish Tanks Get Dirty So Fast – How To Clean And Maintain Tanks

Hence, this same rule applies to a fish tank with Killifish. Killifish also especially appreciate regular water changes.

Nevertheless, if you prefer to keep a filter for your fish tank with Killifish, then which type of filters are the best?

I have also written an article on Aquarium Filtration Methods

What type of Filter should you get for your Killifish?

The first thing to remember is Killifish do not like a lot of water movement. Hence, if you are planning to get a filter that will cause a lot of disturbance in the water, then I would suggest you do otherwise.

The best filter you can get for your Killifish is a sponge filter. These are simple filters with good filtration capabilities.

The air pump in a sponge filter pushes air through the tubing into the hollow cavity inside. This creates bubbles to rise from inside the sponge and draw water through the sponge walls. Through this process, the sponge whilst giving the beneficial bacteria a place to grow collects the debris.

you can choose from either AQUANEAT Aquarium Bio Sponge Filter or hygger Aquarium Double Sponge Filter.

Do you need an Air Pump if you have a Filter?

Another question you may be having is whether you need an air pump if you already have a filter.

The purpose of an air pump is to generate adequate water movement and surface agitation to ensure that your fish get their required supply of oxygen. However, if you are using an external filter (e.g., box or canister filters) then an air pump is not necessary. But if you are using other filters such as a sponge or corner filters, then air pumps can be used.

However, as mentioned earlier, since Killifish do not particularly enjoy water movement, it is best to stick to a good filter that keeps your fish tank clean. As for the air pump, you can leave that out as long as there are enough live plants to provide an abundance of oxygen to your fish.

Do Killifish Need a Heater?

As mentioned earlier, there are 1270 species of Killifish out there. But most Killifish prefer to live in water with temperatures of 72-75oF. Hence, if your room temperature is less than this temperature then you will need to install a heater for your fish tank.

Although, most fish can indeed adapt to a dip in water temperature as this is what happens in nature too. The temperature decreases at night or during rainstorms, causing a dip in the water temperature as well. However, maintaining a steady temperature for your Killifish will prove to cause less stress for your beautiful water pets!

However, which heater is the best for your Killifish?

What type of Heater should you get for your Killifish?

When choosing a heater for your fish tank, the general rule of thumb is 5 watts of heat per 1 gallon of water. For example, if you have a 20-gallon tank, then I would suggest you get a 100 watts heater. Hence, it is not about which heater to get but what size.

So, by using the above-mentioned rule of thumb, you will be able to easily pick out the right heater for your fish tank!

I recommend you to go for Uniclife Aquarium Heater or Penn Plax Aquarium Heater.

How to Keep a Fish Tank Warm without a Heater?

Now, if the room where you keep the fish tank is generally around the required temperature by Killifish, you do not need to purchase a heater. Although, there might be instances when the temperature dips.

As long as you can monitor the temperature of the room regularly, it is not important to get a heater.

However, you can use aquarium lights to keep the fish tank warm without a heater. You can also purchase a light with a timer so that it turns on when the room temperature dips (e.g., at night).

Final Words

In conclusion, you can place live plants in the fish tank to increase aeration, and ensure that your Killifish get the required oxygen. You can also get a sponge filter, which does not cause a lot of water disturbance for your Killifish. Finally, you can use the general rule of thumb to pick out the appropriate heater and keep your Killies nice and warm!

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